This invention relates to a magnetic head unit installed in a magnetic recording and reproduction apparatus for recording information signals, etc., on a loaded magnetic recording medium or reproducing recorded information signals, etc.
A magnetic recording and reproduction apparatus such as a magnetic tape unit, a floppy disk drive, or a hard disk drive is provided with a magnetic head unit for recording information signals, etc., on a loaded magnetic recording medium such as magnetic tape, a floppy disk, or a hard disk or reproducing recorded information signals, etc. Hitherto, various types of magnetic head units have been provided; a multi-channel type hybrid magnetic head unit 50, for example, shown in FIG. 5 is provided as a magnetic head unit compatible with high-density recording. The hybrid magnetic head unit 50 comprises a head block 52 and a support block 53 joined on the whole via a nonmagnetic insulating layer 51 and a flexible wiring board 54 joined at one end to the head block 52.
The hybrid magnetic head unit 50 has an upper end face forming a rounded working face to be abutted against a magnetic recording medium, and is also formed with a large number of magnetic heads 55 arranged in parallel with the running direction of the magnetic recording medium. The nonmagnetic insulating layer 51 is made of aluminum oxide (Al2O3), etc., for example, and is formed as a film on one side of the head block 52. The head block 52 and the support block 53 are formed of nonmagnetic material or magnetic material of alumina, titanium carbide, etc., having a suitable wear resistance or running characteristic.
The hybrid magnetic head unit 50 is formed with a pattern of a plurality of lead terminals 56 drawn out from the magnetic heads 55 on a side of the head block 52 and in particular on the nonmagnetic insulating layer 51 formed as a film on the head block 52. The flexible wiring board 54 is formed at one end part with a plurality of electrode terminals 57 in a one-to-one correspondence with the lead terminals 56. The electrode terminals 57 of the flexible wiring board 54 are connected electrically and mechanically to the corresponding lead terminals 56 with a conductive adhesive, by soldering, etc., for example.
The hybrid magnetic head unit 50 supplies an electric current corresponding to an information signal, etc., to each magnetic head 55 via the flexible wiring board 54 or takes out reproduction output corresponding to an information signal, etc., detected by each magnetic head. A preamplifier 58 (not described in detail) is connected to an opposite end of the flexible wiring board 54, whereby the hybrid magnetic head 50 amplifies reproduction output and transmits the same to a main body unit for signal processing.
Each magnetic head 55, although not described in detail, is made up of a recording head and a reproduction head. The recording head is implemented as an inductive type magnetic head manufactured by executing a thin film process, for example. The reproduction head is implemented as a magnetoresistance effect type magnetic head (MR magnetic head) having a magnetoresistance effect element (MR element) manufactured by executing a thin film process, for example. The MR magnetic head comprises electrodes attached to both ends of the MR element having a magnetoresistance effect film with resistance changing depending on the magnitude of a magnetic field. The MR magnetic head supplies a sense current from the electrodes to the MR element, thereby detecting magnetic field change based on an information signal, etc., recorded on a recording medium as resistance change of the MR element and providing reproduction output. As compared with an induction type reproduction magnetic head, the MR magnetic head features the capability of providing a high output voltage, output independent of the relative speed with a recording medium, and the like.
In the magnetic recording and reproduction apparatus, a high capacity and speeding up are planned by various methods and magnetic recording media of magnetic tape, floppy disks, etc., are also intended accordingly for narrow tracks, etc., in response to high-density recording of information signals, etc. The magnetic head unit makes it possible to provide reproduction output of comparatively large information signals, etc., also from magnetic recording media designed as the high-density recording specifications by using the hybrid magnetic head unit 50.
By the way, the magnetic recording and reproduction apparatus is also intended for recording a record information signal, etc., in a high frequency band on a magnetic recording medium with high-density recording. The magnetic recording and reproduction apparatus provides reproduction output of the information signals, etc., recorded by the magnetic heads 55 of the hybrid magnetic head unit 50 as described above. The hybrid magnetic head unit 50 transmits an extremely weak signal detected by the magnetic head 55 to the preamplifier 58 via the flexible wiring board 54. Thus, in the magnetic heads 55, the extremely weak signal of a high frequency band component detected by the magnetic head 55 is attenuated on a transmission path and a large loss is produced, making it impossible to reproduce the signal with high accuracy.
It is therefore an object of the invention to provide a magnetic head unit for recording and reproducing also an information signal, etc., of a high frequency band component with high accuracy by efficiently amplifying extremely weak reproduction output detected by a magnetic head with a loss on a transmission path suppressed.
In order to achieve the above object, according to the present invention, there is provided a magnetic head unit comprising:
a head body including a magnetic reproduction head provided with a magnetic gap for reproducing at least information signal recorded on a magnetic recording medium;
a lead terminal formed on a side face of the head body and connected with the magnetic reproduction head; and
a preamplifier directly mounted on the side face of the head body, for amplifying a reproduction output from the magnetic gap via the lead terminal.
According to the present invention, there is also provided a magnetic head unit comprising:
a head body including a magnetic reproduction head provided with a magnetic gap for reproducing at least information signal recorded on a magnetic recording medium;
a lead terminal formed on a side face of the head body and connected with the magnetic reproduction head;
a flexible wiring board one end portion of which is connected with the lead terminal; and
a preamplifier directly mounted on the end portion of flexible wiring board, for amplifying a reproduction output from the magnetic gap via the lead terminal.
According to the magnetic head unit according to the invention thus configured, the reproduction output detected by the magnetic gap is amplified by the preamplifier placed at a position near the magnetic gap, so that the loss on the transmission path of the flexible wiring board, etc., can be minimized. Therefore, the magnetic head unit records and reproduces, with higher accuracy, also the information signal, etc., of a high frequency band component accompanying high-density recording, such as an information signal, etc., on a magnetic recording medium.